The threshing mechanism of a harvester typically includes a threshing rotor and an underlying concave which cooperate to thresh the grain or seeds from the crop passing between the rotor and the concave. The crop is delivered to the threshing mechanism by a feeder receiving the cut crop from the header located forwardly of the harvester. Occasionally, when the combine or the harvester is operating in rocky regions, the header will pick up a rock along with the crop, and unless the rock is removed before it enters between the threshing rotor and the cooperating concave, extensive damage may be caused to the threshing mechanism.
It is well known to provide a safety door or rock trap to intercept rocks or the like before they pass to the space between the threshing rotor and the concave. One such safety door is shown in U.S. Pat. No. 4,195,644. In the before mentioned patent there is illustrated a safety door which is hinged at its forward end and includes a pivotable detented lip, the rear edge of which rests on a forward edge of the concave. The present invention is directed to substantially improve the function and operation of a safety door of the type shown in the before-mentioned U.S. Pat. No. 4,195,644.